1. Technical Field
The present invention relates to a semiconductor device and a method of designing the same, and in particular to a semiconductor device having an interposer and a semiconductor chip disposed thereon, and a method of designing the same.
2. Related Art
Semiconductor packages are generally configured by mounting an interposer on a mounting substrate while placing solder balls in between, and by disposing semiconductor chip(s) further thereon. However, there has been known a problem of deformation of semiconductor packages due to unbalanced stress exerted by the semiconductor chip(s) to the interposer, for the case where the semiconductor chip(s) have a rectangular geometry in a plan view, or for the case where the center of the interposer does not coincide with the center of the semiconductor chip(s). This sort of deformation may cause warping or other non-conformities of the interposer, and may degrade lifetime of connection by the solder balls between the interposer and the mounting substrate.
Japanese Laid-Open Utility Publication No. S62-37964 describes a printed circuit board having a protective substrate bonded to the surface thereof on the component-mounting side, wherein the protective substrate is provided with through-holes corresponding to the position of attachment of components to be mounted, so as to incorporate the components therein.
However, in the technique described in Japanese Laid-Open Utility Publication No. S62-37964, any alteration in layout of the components to be mounted (semiconductor chip, and so forth) inevitably needs alteration of geometry of the protective substrate, and therefore raises a problem of limited degree of freedom in design, and large cost.